Примерно так должно работать:
import pandas as pd
from datetime import datetime
data = ["1983-02-07",
"1989-10-07",
"1969-10-28",
"1967-02-25",
"1982-07-21"]
df = pd.DataFrame(data, columns = ["Date"])
print(df)
df["Date"] = pd.to_datetime(df['Date'])
#df["Difference"] = df["Date"].apply(lambda x: x-datetime.now())
# Alternate code
from dateutil.relativedelta import relativedelta
df["Difference"] = df["Date"].apply(lambda x: relativedelta(datetime.now(), x).years)
print(df)
Вывод:
Date
0 1983-02-07
1 1989-10-07
2 1969-10-28
3 1967-02-25
4 1982-07-21
Date Difference
0 1983-02-07 -13409 days +06:41:00.418879
1 1989-10-07 -10975 days +06:41:00.418728
2 1969-10-28 -18259 days +06:41:00.418671
3 1967-02-25 -19235 days +06:41:00.418630
4 1982-07-21 -13610 days +06:41:00.418591
КОД ВЫХОДНОГО АЛЬТЕРНАТА:
Date
0 1983-02-07
1 1989-10-07
2 1969-10-28
3 1967-02-25
4 1982-07-21
Date Difference
0 1983-02-07 36
1 1989-10-07 30
2 1969-10-28 49
3 1967-02-25 52
4 1982-07-21 37